Theory of Operation

An appeal of visual level indicators (VLI's) is their ability to monitor the level within a vessel while still maintaining the process inside a sealed chamber. A wide variety of mounting configurations are available to ensure both a safe and easy installation. VLI's eliminate the hazards and leakage of sight glasses. With optional switch and transmitter attachments, VLI's are also less expensive than a system of sight glasses, alarm switches and transmitters - all separately piped to the vessel.

A float with internal magnets moves within the VLI chamber. As the liquid rises and falls within the process tank, the float travels with the corresponding fluid level inside the chamber. An isolated visual indicator housing is attached to the exterior containing a string of dual color magnetic flags that rotate as the float passes. The point at which the flag color has changed on the indicator directly correlates to the liquid level within the process tank.